Rolling mill screw down arrangement



Sept. 7, 1937. PEARSON I 2,092,224

ROLLING MILL SCREW DOWN ARRANGEMENT Filed Oct. 22, 1935 5 Sheets-Sheet l -:Zz 2? 2.5 i I m /5 2/ I6 I I /9 3 :1! f z 17 A 2 I I4 l5 [now ([07? 142191 5. PEAESO/V, 55

Sept. 7, 1937 A. B. PEARSON ROLLING MILL SCREW DOWN ARRANGEMENT Filed Oct. 22, 1 935 3 Sheets-Sheet 2 V Inventor; 4x54 5 PEQESO/V,

p 1937. A. B. PEARSON ROLLING MILL SCREW DOWN ARRANGEMENT Filed Oct. 22, 1955 3 Sheets-Sheet 3 [mm d022- A XEL 5. PEQESON,

Patented Sept. 7, 193? pairs star gram rarer or ies Axel B. Pearson, Munhall, Pa.

Application October 22, 1935, Serial No. 46,176

3 Claims.

This invention relates to rolling mills and particularly to mills that handle the heavier type of work, such as blooming mills and the like, one of the objects being to prevent the screwdown settings of such mills from being destroyed by the shocks and vibrations experienced during their operation. Other objects may be inferred.

Referring to the accompanying drawings which illustrate a specific example of the present invention:

Figure 1 is a fragmentary view of the top of a mill to which this example is applied.

Figure 2 is a section from the line IIII in Figure 1.

Figure 3 is an enlargement showing details of this example as it appears in Figure 2.

The above mill includes working rolls I that are journaled in housings 2 and provided with screwdowns 3. These screwdowns are threaded through elements in the mill top 4 and are slidably connected with bevel gears 5 located above. These gears 5 are interconnected by a shaft 6 through pinions 'l with which they are meshed.

The mill being described is conventional insofar as the above elements are concerned. It is generally considered desirable to power the shaft ii that operates the screwdowns 3 with an electric motor system because this facilitates the control of the mill. Since the screwdowns are not operated during the time work is between the rolls i, it is not necessary or desirable to provide this system with much power. Therefore, difiiculties are experienced in maintaining proper screwdown settings during the operation of the mill, the heavy shocks and vibrations encountered causing rotation of the screwdowns, particularly as the work starts between the rolls.

It is to be noted that the settings cannot be corrected until the work leaves the rolls, since the screwdown operating system is not sufficiently powerful to move the screwdowns when they are transmitting working pressures to the rolls. The diificulty being described is even more apparent when the various moving parts involved by the screwdown operating mechanism are properly lubricated, it being quite common to use an improper grade of lubricant and to permit dirt to accumulate on the moving parts for the sole purpose of providing greater friction. The undesirability of the latter procedure is obvious.

According to the present invention, a train of gears, the gears in this train being respectively numbered 8, 9, and it, connects the shaft 6 to reversing electric motors H that are provided with the usual electromagnetically released brakes l2. Assuming the various moving parts to be properly lubricated and protected from dirt, these brakes I2 are insufiicient to positively lock the screwdowns 3 against rotation during the 5 operation of the mill. As has been described, it is customary to deliberately increase the friction involved by these various moving parts so as to increase the effect of the brakes l2. However, even this resort often fails to provide for 10 the adequate locking of the screwdowns, and in the case of a blooming mill oversize work that causes serious damage in following mills is all too frequently encountered.

Continuing, the two adjacent gears 9 and l8 in the gear train that interconnects the shaft 6 and motors II are fixed to shafts i3 and I4 that carry relatively soft metal collars i5 and i6, and cooperative jaws l? are arranged about both of these collars. These jaws ll are provided 2 with relatively hard metal inserts [8 that provide teeth which dig into the soft metal collars upon clamping action of the jaws.

Clamping action of the jaws i7 is effected by a reciprocating motor I9 whose operating rod 20 connects with the end of a lever 2! that is pivoted at 22 and has a cam end 23 that bears against a cam surface 24 formed in the top of the jaws H, the jaws I'i being interconnected by a link 25 whose upper end pivots at 22 and whose lower end is pivoted at 26. The arrangement just described provides a cam-and-lever system for effecting clamping action of the jaws, this system being operatively connected with the motor l9. Springs 2'1 are positioned between the jaws I! so as to assure unclamping action upon proper operation of the reciprocating motor l9, and bolts 28 are arranged to adjustably limit the operation of these two jaws. 40

In operation, the reciprocating motor I9 is operated to swing the lever 2! to the left so as to unclamp the jaws ll from the collars l5 and [6. The screwdowns may then be set by operation of the motors H. After this, the recipro- 5 cating motor 59 is operated to throw the lever 2! to the right so as to clamp the jaws i7 about the collars l5 and [6, the teeth of the inserts l8 digging into these collars. This action inter locks the two gears 9 and I0 against rotation re- 50 gardless of the shocks and vibrations experienced during the operation of the mill. It is to be understood that the jaws l7 and the described cam-and-lever system are suificiently strong to resist the forces involved in so looking the gears 55 Sand i0.

It isto be particularly noted that the positive locking of the screwdowns against rotation relieves the brakes l2 of this responsibility. Further, it permits the moving parts involved by the screwdown operating mechanism to be properly lubricated and otherwise maintained in a workmanlike manner.

I claim:

1. A blooming mill or the like including the combination of working rolls, screwdowns for said rolls, a train of gears geared to said screwdowns, said mill being subject to jarring when the work enters said rolls, and means for interlocking at least two of the gears in said train against notation.

2. A blooming mill or the like including the combination of working rolls, screwdowns; for

said rolls, a train of gears geared to said screwdowns, said mill being subject to jarring when the work enters said rolls, rotary elements arranged to rotate with two adjacent gears in said train and a clamp constructed and arranged to clamp about both of said elements so as to interlock the same and prevent rotation of either.

3. A blooming mill or the like including the combination of working rolls, screwdowns for said rolls, a train of gears geared to said screwdowns, a motor driving through said train, soft metal rotary elements connected to two adjacent gears in said train, cooperative jaws arranged about both of said elements and having hard metal teeth for engaging the latter, a cam-and-lever system for effecting clamping action of said jaws, and a reciprocating motor operatively connected with said system.

AXEL B. PEARSON. 

